X has bought one house property in 2015-16,
this property was dismantled and sold as a plot of land in 2019-20
LTCG for Real estate is 2 years.. earlier it was 3 years...
so it is a LTCG...
If you Treat it as Residential Property you can Claim Deduction us 54 of Income Tax if you Purchase another Residential Property within 2 years (However sec 54 says that the Residential Property sold must have been charged under House Property) If you have filed ITR please check if it shown in Previous ITR as House Property..
Us 54F you can claim Deduction if it is not treated as Residential Property and if You purchase a Residential Property within 2 years.. However this deduction will not be available if you already have more than One Residential Property..